• Journal of Environmental Science International
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• v.14 no.10
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• pp.965-972
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• 2005

This research studied the effect of factors that are able to form disinfection by-products (DBPs) of chlorination, including natural organic matter (NOM) with sewage, bromide ions, pH and contact time. Trihalomethane (THMs) yield of $0.95{\mu}mol/mg$ was higher than other DBPs yield for the chlorinated humic acid samples. THMs yield of sewage sample was $0.14{\mu}mol/mg$ and haloacetonitriles (HANs) yield in the sewage samples were $0.13{\mu}mol/mg$ but only $0.02{\mu}mol/mg$ for the humic acid samples. As the concentration of bromide ions increased, brominated DBPs increased while chlorinated DBPs decreased, because bromide ions produce brominated DBPs. THMs were highest $(55.55{\mu}g/L)$ at a pH of 7.9 and haloacetic acids (HAAs) were highest $(34.98{\mu}g/L)$ at a pH of 5. Also THMs increased with increasing pH while HAAs decreased with increasing pH. After chlorination, the rate of THMs and HAA formation are faster at initial contact time and then reaches a nearly constant value after 24 hours. This study considers ways to reduce DBP formation by chlorination.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.5
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• pp.534-539
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• 2013

To secure the biological safety of live fish and shellfish for raw consumption, the germicidal effects of electrolyzed seawater were evaluated. Upon direct exposure to electrolyzed seawater, coliform group bacteria were killed and decreased to undetectable levels after 1 day. The physicochemical characteristics of the seawater were stable during the test period. A byproduct of chlorine disinfection, trihalomethane, was not generated by the electrolysis of seawater. Vibrio parahaemolyticus infection in a live fish was effectively resolved by electrolyzed seawater and became undetectable after 12-36 h of treatment. Bioaccumulation of coliform group and fecal coliform bacteria in live oysters Crassostrea gigas was removed within 18 h of treatment. This study demonstrated that electrolyzed seawater is an effective and safe germicidal agent for the traditional retail market and can help to prevent outbreaks of foodborne disease associated with the consumption of raw fish and shellfish.

• Journal of Environmental Health Sciences
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• v.24 no.2
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• pp.38-46
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• 1998

The purpose of this study is to evaluate and compare the effective coagulation of commercial humic acid which is well known as major precursor of trihalomethane, with LAS and PAC and to quantify the residual aluminum in the treated water. Then the optimum pH, the dosage of coagulant were determined. 1. Humic acid concentrati6n, UV absorbance and color were well correlated and UV absorbance(254 nm) and color seem to be used in quntificative analysis of humic acid of same kind. 2. Optimal dosage of LAS and PAC increase as humic acid concentration increases. And optimal pH range for coagulation using LAS is pH 5.5-7.0 and pH 3.5-6.5 for PAC. Within these ranges the removal efficiency is 90-99%. 3. The results of quantification of residual aluminum in treated water shows that minimal aluminum remains on the optimal coagulation condition. But the residual aluminum increses as the dosage of coagulant is beyond the optimal range. Thus the dosage of coagulant should be chosen with the condition on which humic acid removal is maximum and the residual aluminum concentration is minimum. 4. In the water treatment process the raw water pH range is 6.5-8.0, and it seems to be possible to remove humic acid by charge neutralization not by sweep floc. But it should be considered that different commercial humic acids have different physical and chemical characteristics.

• Journal of environmental and Sanitary engineering
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• v.4 no.1 s.6
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• pp.7-15
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• 1989

According to the increase of population and development of industrialization air and water pollution problems are still keeping going to great nuisance to human activities. Specially man should drink 2l clean water to maintain our health every day, but we afraid of drink the city tap water because of the contaminants like heavy metals, bacteria trihalomethane, etc. In the analysis of the anions in potable water, we usually adapt the Standard methods for the Examination of Water and Wastewater. But this method is tedious and time consuming, so the Ion Chromatography method is now used in research of water quality. Author worked with Ion Chromatography in measuring the anions in drinking water by attaching conductivity dector to normal High Performance Liquid Chromatograph. Low-capacity ion-exchange coulmn and dilute eluents, 0.00M phthalic aic was used in this study. The concentration of chloride ion was 1.55 ppm$\~$3 8.81ppm, nitrate ion was 5.45 ppm$\~$18.27ppm, and sulfate ion was 19.64 ppm$\~$28.86 ppm. The phosphate ion was detected only in Apt. tap water as 167.99 ppm whose amount was supposed to be used as a water pipe cleaner.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.1
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• pp.37-46
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• 2007

A feasibility test was conducted to evaluate the addition of turbidity substance in a coagulation process to remove natural organic matters (NOM), the precursor of disinfection by-products (DBPs). The experimental water sources were synthetic water containing 5 mg/L of humic acid and 50 mg/L of NaHCO3 and drinking water resource of Ulsan city (S Dam water, D Dam water and Nak-Dong raw water). The examined turbidity substances were kaolin, acid clay, and modified clay (0.38 meq $NH_4{^+}-N/g$ clay). In Jar tests at different concentrations of the turbidity substances (5, 10, 15, 20, 30 mg/L) using the synthetic water, the turbidity substances improved the removal of turbidity, UV-254 absorbance and dissolved organic carbon (DOC) by 23.8-38.1%, 17.0-24.5% and 2.5-44.5%, respectively. The modified clay showed higher removal efficiencies than other substances. In Jar tests using the drinking water, 10 and 20 mg/L of modified clay enhanced the removal efficiencies of turbidity, UV-254 absorbance, DOC, trihalomethane formation potential (THMFP), and haloacetic acid formation potential (HAAFP) by 3.0~4.3%, 19.1~29.0%, 12~34.9%, 4.9~36.7%, and 1.6~30.2%, respectively.

• Journal of Environmental Health Sciences
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• v.26 no.4
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• pp.122-128
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• 2000

This study was carried out to survey trihalomethane formation potential(THMFP) levels in drinking underground water and to examine its characteristics in Kunsan area. In drinking underground water, THMFP increased with the lapse of reaction time and 96hr-THMFP was the highest of THMFPs examined. In many cases, 24hr-THMFP, 48hr-THMFP and 96hr-THMFP reflected 2hr-THMFP level due to the largest composition ratio of CHCl$_3$ decreased with the lapse of reaction of CHCl$_3$ among THM individuals. CHCl$_3$ was mostly formed within early 2hour of reaction time, but CHClBr$_2$ and CHBr$_3$ continued their formation until 48 hour. Accordingly, the composition ratio of CHCl$_3$ decreased with the lapse of reaction time while that of total Br derivatives increased. 96hr-THMFPs of drinking underground water in Kunsan area ranged from N.D.(not detected)~98.80 $\mu\textrm{g}$/$\ell$ and, in general, those of western section of Kunsan area, closer to the coast, showed the higher tendency. But, from their large range of variance, it could be considered that THMFPs differ individually even in the same section depending on such factors as the difference of water stream, circumstances of management and so on. All the parameters for water quality examined(pH, KMnO$_4$ consumption;UV$_{254}$ , TOC. Cl$^{[-10]}$ ) showed very week corelation with 96h-THMFP.

• Journal of Korean Society of Water and Wastewater
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• v.11 no.4
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• pp.126-132
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• 1997

Trihalomethanes (THMs) are formed during the chlorination of waters containing precusors compounds, most commonly humic substances, changes in pH, TOC, temperature, precusor source and concentration chlorine dosage, bromide level and reaction time directly influence trihalomethane formation potential (THMFP) and kinetics. A standard THMFP experiment was conducted for each water under the following conditions ; $20^{\circ}C$, pH 7.4, reaction time of 48hr, TOC 5.7mgC/L. A series of kinetic experiments was conducted for each water to provide THM formation under varying conditions of reaction time, pH, temperature and TOC, chlorine dosage. The resultant mutiple parameter powre function predicts a THM which allows direct calculation of THM, is $[THM]=0.00039(pH-2.81)[TOC][Cl_2]^{0.321}\;t^{0.266}\;T^{0.286}$ Characteristics of raw water in advanced drinking water treatment pilot plant were, TOC levels ran from 4.42~6.84mgC/L, pH 7.2~7.8, temperature $7.0{\sim}18.4^{\circ}C$, UV-254 absorbance $0.057{\sim}0.85cm^{-1}$, THM levels ranged from 0.031~0.049mgC/L.

• Journal of Korean Society of Water and Wastewater
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• v.13 no.3
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• pp.83-90
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• 1999

This study was carried out to investigate the characteristics of trihalomethane (THM) formation from chlorination of groundwater in the northeastern area of Cheju Island. Effects of total organic carbon (TOC) and bromide in groundwater on the THM formation were studied. Samples were taken from two regions withe altitude. The concentrations of TOC and bromide in groundwater were higher at the regions of lower altitude, especially at the altitude below 50m. Generally the THM formation in GA region containing a high TOC was higher than that in GB region containing a relatively high bromide. At the altitude below 100m, the formation of total and brominated THM was highest at GB region. The most part of THM formation was brominated THM at GB region. The formation ratio of chloroform and brominated THM was similar to the others. Among the brominated THM, dibromochloromethane and bromoform in GB region were containing high bromide. Bromodichloromethane and dibromochloromethane in GA region were containing low bromide. At the altitude above 200m, chloroform was formed mainly. Comparing the ratio of brominated THM of total THM in Cheju Island with that in other areas, Seoul and Pusan, it can be konwn that the former showing 51.3% was much higher than the latter showing 6.7% and 28.8%, respectively.

• Journal of Preventive Medicine and Public Health
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• v.16 no.1
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• pp.79-88
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• 1983

There has been some evidence concerning the fact that trihalomethanes(THMs), toxic chlorinated compounds, may be present in drinking water. One of the important methodologies to evaluate the toxicity of THMs is to determine enzyme alteration in experimental animal tissues after treatment. This study was intended to investigate how lactic dehydrogenase(LDH) of rat tissues is affected by administration of chloroform($CHCl_3$) and dichloromonobromomethane($CHCl_2\;Br$). THMs, high dose(1/10 LD50) or low dose(1/50 LD50) of $CHCl_3$ or $CHCl_{2}Br$ were administered orally to experimental rats for 4 or 8 weeks. The treated groups of rats were sacrificed to determine LDH specific activity and isozyme pattern in various organs which were liver, thigh muscle, kidney and brain. The conclusions were obtained as follows: 1. Alteration of LDH activities and isozyme patterns were revealed before morphologic changes in tissues. 2. The LDH specific activities were increased significantly in liver and brain after administration of high concentrations of $CHCl_3$ and $CHCl_{2}Br$ for 4 weeks respectively. Otherwise, they were decreased significantly in liver, muscle and kidney after administration for 8 weeks. 3. The isozyme activities of LDH-4 and LDH-5 were increased in muscle, brain, and especially the liver. 4. It was more distinct for the decrement of LDH H-type isozyme than the increment of M-type isozyme in muscle.

• Journal of Environmental Health Sciences
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• v.39 no.3
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• pp.223-229
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• 2013

Objectives: In an effort to examine the distribution of THMs (Trihalomethane) generated from chlorine disinfection by the drinking water treatment plants located on the east coast region of Gangwon-do, this study surveyed the distribution and concentrations of each component of THMs twice per month for 5 years from 2008 to 2012. Fluctuation pattern in the seasonal generation amount was identified. In addition, the correlation between the concentration of organic substances in water and THMs was assessed, along with stability of purified water quality supplied by the water treatment plants on the east coast by analyzing the composition ratio of each component that constitutes THMs and the detection frequency. Method: The research was done on purified water supplied by 29 water treatment plants in 7 cities and counties (Goseong-gun, Sokcho-si, Yangyang-gun, Gangneung-si, Donghae-si, Samcheok-si, Taebaek-si) located in Gangwon-do on the east coast. Water samples were collected twice a month from 2008 to 2012 and were investigate for chloroform, bromodichloromethane (BDCM), dibromochloromethane (DBCM), and bromoform, based on analysis through Purge-Trap (Tekmar 3000) devices using FID-attached GC (HP 6890, Hewlett Packard). Result: THMs concentration detected at Gangneung-si was 0.0086mg/L, Goseong-gun 0.0019mg/L, Donghae-si 0.0099 mg/L, Samcheok-si 0.0016 mg/L, Sokcho-si 0.0057 mg/L, Yangyang-gun 0.0027 mg/L and Taebaek-si 0.0038 mg/L. As the THMs composition rate, chloroform constitutes 51.4% followed bybromodichloromethane 22.3%, bromoform 15.2% and dibromochloromethane 11.1% respectively. Conclusion: Throughout the entire THMs survey areas and period, the maximum concentration was 0.072mg/L, which did not exceed the water quality standards (0.1 mg/L), and the overall average concentration was very low at 0.0044 mg/L.